Electroluminescent bulb



s. nu N V/ wn e i td n.. t eGKt VYrA mr e H M if H/ f Y IO H. G. JENKINS ELECTROLUMINESCENT BULB Filed Dec. 2, 1952 Aug. 2, 1955 Gianni,

0.25% by weight of copper in the dried mixture, the the latter being ground thoroughly and fired at 800900 C. in a closed boat for several hours.

The conducting coating may be applied by spraying or painting the layer 4 with a suitable conducting material but is preferably applied by the evaporation of a suitable metal such as aluminum. This evaporation may convenientiy be effected by attaching a short length of Wire of the metal between the leads 7 and 8, as indicated by the dotted line 18 in the drawing, and after evacuation of the bulb7 heating the Wire by the passage of current through it, with the bulb support neck downwards, so as to evaporate the wire and form the required coating, an insulating bae 19 attached to the leads 7 and 8 preventing the possibility of the evaporated metal short-circuiting the two conducting coatings at the neck of the bulb. The bulb is then filled with dry nitrogen to atmospheric pressure and sealed, after which the cap is attached to the neck of the bulb.

While a certain specic embodiment of the invention has been shown and described, various modiications thereof are possible, and the appended claims are intended to cover any such modications coming within the scope of the invention.

The alkyd resin known under the British trade name Paralac 1G is a long-oil linseed oil Inodiiied alkyd resin containing pentaerythritol and no added glycerol.

What l claim as new and desire to secure by Letters Patent of the United States is:

1. An electroluminescent lamp comprising a transparent bulb sealed free of moisture and having a conductive inside surface, a layer containing an electroluminescent material formed over said conductive surface, a conductive layer formed over said electroluminescent material layer, and lead wires sealed into said bulb and connected, one to said conductive surface and the other to said conductive layer.

2. An electroluminescent lamp comprising a vitreous bulb sealed free of moisture, a conductive coating formed on the inside surface of said bulb, a layer containing an electroluminescent phosphor formed over said conductive coating, a conductive layer formed over said electroluminescent layer, and a pair of lead Wires sealed into said bulb and connected, one to said conductive coating, and the other to saidconductive layer.

3. An electroluminescent lamp comprising a vitreous bulb, a conductive coating formed on the inside surface of said bulb, a layer of dielectric material containing a dispersion of an electroluminescent phosphor formed over said conductive coating, a conductive layer formed over said electroluminescent layer, a pair of lead wires sealed into said bulb and connected, one to said conductive coating and the other to said conductive layer, and a filling of a dry gas seaied within said bulb.

4. An electroluminescent lamp comprising a vitreous bulb, a conductive coating formed on the inside surface of said bulb, a layer of an electroluminescent phosphor in a dielectric binder adherent to said conductive coating, an insulating layer of a dielectric material adherent to said electroluminescent layer, a conductive layer formed over said insulating layer, a pair of lead wires sealed into said bulb and connected, one to said conductive coating and the other to said conductive layer, and a filling of a dry gas sealed within said bulb.

5. An electroluminescent lamp comprising a vitreous bulb, a conductive coating formed on the inside surface of said bulb, a layer of a zinc sulphide phosphor in an alkyd resin adherent to said conductive coating, an insulating layer of an alkyd resin adherent to said phosphor layer, a conductive layer of evaporated metal adherent to said insulating layer, a pair of lead Wires sealed into said bulb and connected, one to said conductive coating and the other to said conductive layer, and a nlling of a dry gas sealed within said bulb.

References Cited in the tile of this patent UNITED STATES PATENTS Light, by E. C. Payne, E. L. Mager and C. W. Jerome, Illuminating Engineer, November 1950, pp. 688-692. 

1. AN ELECTROLUMINESCENT LAMP COMPRISING A TRANSPARENT BULB SEALED FREE TO MOISTURE AND HAVING A CONDUCTIVE INSIDE SURFACE, A LAYER CONTAINING AN ELECTROLUMINESCENT MATERIAL FORMED OVER SAID CONDUCTIVE SURFACE, A CONDUCTIVE LAYER FORMED OVER SAID ELECTROLUMINESCENT MATERIAL LAYER, AND LEAD WIRES SEALED INTO SAID BULB AND CONNECTED, 